Liquid-type structure near-infrared light-emitting diodes based on PbSe quantum dots for acetylene gas detection

Abstract

Among near-infrared (NIR) absorption spectroscopy technique, an important limiting element is NIR light source, which will directly affect the performance of the gas detection system. In this paper, a liquid-type structure NIR light-emitting diodes (LEDs) based on PbSe quantum dots (QDs) is developed. Employing the NIR PbSe QDs LEDs, gas cell with ellipsoid reflector, photoelectric detector, STM32 main controller and signal processing module, a NIR gas differential detection system is designed to monitor acetylene gas. The experimental results show that the detection limit of the system is 10 ppm, and the maximum relative error of the system is less than ±3%. A long-term measurement lasting for 20 h with the concentration of 200 ppm suggest that the system has good stability and reliability. Benefitting from the advantages of simple fabrication, narrow band, small size and easy tunability, the liquid-type NIR QDs-LEDs have great potential for gas analysis.